We were away for ten days. Upon return the toilet in our master bedroom stopped working. The toilet was working fine before we left. I should add that while we were away the outside temps were in the 20 - 35 degree F range. Now when we flush the toilet there is no water flowing into the toilet tank.. . None. Can someone provide some insight. And yes, the water valve is in the full on position (as no-one touched it while we were away)

Is this an older toilet (say 10-20 years) or a newer toilet?

If older toilet then would recommend that you replace the ballcock assembly with a fluidmaster 400 or similar unit (all home supply stores sell).

If newer unit you may be able to shut off water supply and push down on top of the fluidmaster (or similar) assembly and twist unit top off to expose the washer underneath the cap (look on top... should see instructions to twist off).

Then, pull washer out and put cloth over top and turn water on. Is water present when you do this? If so.. should just need to clean washer and replace top. If not, problem is further back.

There are other types of fill valves as well... but not so easy to access washer assembly.

In fact, I would just replace the fill valve... Just shut off water, loosen flexible or solid connector from the shutoff to the toilet, drain water out of tank, loosen nut holding fill valve in place, then install new fill valve (do not overtighten). Then re-attach water line (if solid will need to cut... or just buy a flexible riser when getting the fill valve... 3/8"compression x toilet nut riser should do it). Then adjust height of fill valve to stop water flow about 1 " below the overflow tube at center of toilet... this job, once you have the fill valve should take 15-20 minutes... let us know how it works out!!

Is the toilet float moving and free, or stuck in the up position? Try moving it up and down by hand. If it starts working great, but still may require the steps posted by massplumber.

Good luck